The weight of tanks is often sought to be reduced by making the walls thinner and/or from lighter materials such as plastic sheet. Using lighter/thinner materials however can consequently lead to a decrease in the strength of the tank. The tanks are therefore prone to bulging and deformation when carrying a load.
It would therefore be beneficial to have a tank which has a both strong and light weight construction. Preferably, the tank whilst having relatively thin walls may still provide a robust construction, which is the same, or substantially similar, to that achieved with heavier tanks. In addition, a light weight tank construction which can better withstand damage that would occur from explosive, or other, forces that could cause rupture, would be advantageous.
Many tanks used in vehicles have a large capacity. As the vehicle moves, this causes the liquid in the tank to also move resulting in “sloshing” which can adversely effect the vehicle's movement as it alters the centre of gravity. This is of particular concern in boats where the relative orientation is important in its performance.
To combat “sloshing” baffles are used in tanks control the flow of liquid in the tank. U.S. Pat. No. 7,028,382 is one example of a method of constructing a tank with baffles. According to this patent, a framework is first constructed having plates which provide the end walls of the tank, and baffles transverse and longitudinal to the length of the tank.
The body of the tank is completed by wrapping sheet material around the framework to form the tank's side and bottom walls. A top is subsequently secured over the framework and to the edges of the side walls.
However, tanks produced using the method disclosed by this patent are particularly weak as the top is only welded to the side and end walls
In addition, the baffles formed by the initially constructed framework are ineffective at controlling movement of liquid in the tank. This is because the liquid is still able to run up the sides of the baffles and therefore alter the centre of gravity of the tank.
Therefore, it would be a benefit to have a method of constructing a stronger tank made from thin and/or light weight materials.
Further, it would be advantageous to have a tank having baffles which better control the movement of liquid within the tank.
All references, including any patents or patent applications cited in this specification are hereby incorporated by reference. No admission is made that any reference constitutes prior art. The discussion of the references states what their authors assert, and the applicants reserve the right to challenge the accuracy and pertinency of the cited documents. It will be clearly understood that, although a number of prior art publications are referred to herein, this reference does not constitute an admission that any of these documents form part of the common general knowledge in the art, in New Zealand or in any other country.
It is acknowledged that the term ‘comprise’ may, under varying jurisdictions, be attributed with either an exclusive or an inclusive meaning. For the purpose of this specification, and unless otherwise noted, the term ‘comprise’ shall have an inclusive meaning—i.e. that it will be taken to mean an inclusion of not only the listed components it directly references, but also other non-specified components or elements. This rationale will also be used when the term ‘comprised’ or ‘comprising’ is used in relation to one or more steps in a method or process.
It is an object of the present invention to address the foregoing problems or at least to provide the public with a useful choice.
Further aspects and advantages of the present invention will become apparent from the ensuing description which is given by way of example only.